Arterial blood, which supplies the heart muscle, is able to pass through healthy heart tissue while nourishing the same, yet has difficulty reaching ischemic tissue. As a result, the supply of ischemic tissue with nutrients and the discharge of metabolic catabolites from such ischemic tissue will be impaired.
In this context, it has already been proposed to supply the ischemic tissue with blood through retrograde perfusion. To this end, it has already been proposed to use an inflatable balloon fixed to the end of a catheter to intermittently occlude the coronary sinus. The blood pressure in the coronary sinus rises during the occlusion at every heart beat so as to cause blood reaching the coronary sinus through the healthy tissue of the heart muscle to be flushed back into the ischemic tissue. For such an intermittent coronary sinus occlusion, the balloon end of the catheter is inserted either percutaneously or surgically. The other end of the catheter is supplied with a gas or fluid by a pump, which causes the cyclic inflation and deflation of the balloon.
A device for the retroinfusion of coronary veins is, for instance, known from WO 2005/120602, by which a pressure-controlled, intermittent coronary sinus occlusion can be performed. In that device and the associated method for determining the optimum times for triggering and releasing the occlusion, pressure parameters like the speeds of the pressure increase and pressure drop were determined and subjected to relatively complex processing. That previously known device, however, involved the drawback that, at a release of the occlusion, the catheter and, in particular, the free end of the catheter was no longer guided in the coronary sinus, as would be the case if the balloon were inflated. As a result, the catheter was able to move freely within the vessel upon release of the occlusion, thus causing the pressure measuring devices, which are usually arranged in the end region of the catheter, to deliver imprecise measuring data at a contact of the vessel wall and a number of artefacts to negatively influence the data determined for calculating the occlusion times. The thus determined data of minor quality subsequently rendered difficult the precise and reproducible determination of the times suitable as occlusion start and end points.